1. Field of the Invention
This invention relates to a system for effecting mutual authentication between a portable type electronic device such as an IC card having an IC (integrated circuit) chip enclosed therein and a host device or terminal device.
2. Description of the Related Art
In order to effect the mutual authentication between the IC card and host device, first authentication data and first key data stored in the IC card are transferred to the host device and stored therein, second authentication data and second key data stored in the host device are transferred to the IC card and stored therein, and the second and first authentication data are encrypted by use of second and first key data, and supplied back to the host device and the IC card, respectively, for authentication.
As described before, in the mutual authentication system with the above construction, memory areas for holding four different types of data, that is, first authentication data and first key data to be transferred to the host device and second authentication data and second key data transferred from the host device must be provided in, for example, a RAM of a CPU in the IC card. Likewise, memory areas for holding four different types of data must be provided in a CPU in the host device.